Re: can event handler call event source passed as connection point parameter?

From:
"Igor Tandetnik" <itandetnik@mvps.org>
Newsgroups:
microsoft.public.vc.atl
Date:
Thu, 28 Sep 2006 12:49:09 -0400
Message-ID:
<uZnbF4x4GHA.1252@TK2MSFTNGP04.phx.gbl>
Xudong <chenxudongsg@gmail.com> wrote:

What's weird here is that if I do a redundant QueryInterface on the
pointer for its own type, the code runs normal! The code is similar to
following:

// event source in free threaded DLL
class CServer ... {
   Fire_OnSomeEvent(IServer* ptr) { // ATL generated
       ...
       HRESULT hr = Invoke(...);
       ...
   }

   SomeMethod() {}
};

// event handler in apartment threaded EXE
class CClient ... {
   void __stdcall OnSomeEvent(IServer * ptr) {
       ptr->QueryInterface(IID_IServer, (void**)&ptr); // line X
       ptr->SomeMethod(): // line Y
   }
};

With line X, everything works fine and line Y does call through
SomeMethod().


Show the definition of IServer. What kind of interface is it - dual,
automation, custom? Show the definition of OnSomeEvent: what type
parameter is it declared to have?
--
With best wishes,
    Igor Tandetnik

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necessarily a good idea. It is hard to be sure where they are going to
land, and it could be dangerous sitting under them as they fly
overhead. -- RFC 1925

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